01 CR125 forks on a 220

UFS207 · Post by **UFS207** » 12:07 am Jan 20 2007

Hope it is OK if I post this here:

I recently bought a set of 2001 CR125 forks plus triple tree clamp off ebay with the intent of mounting it up on my 220. Completely unresearched impulse buy. I figured if worse came to worst I'd just put them back on ebay and hopefully get most of my money back. I was just wondering if anyone has attempted something similar?

I assume I will, at the very least, be making a custom axle, brake caliper mount and a spacer for the steering stem. I work in a machine shop which is the only reason I even thought attempting this would worthwhile.

Any thoughts, suggestions on such a swap would be greatly appreciated.

krazyinski · Post by **krazyinski** » 09:46 am Jan 20 2007

good luck, and keep us posted on your findings

canyncarvr · Post by **canyncarvr** » 07:58 pm Jan 23 2007

Pretty much any fork will fit anything with the right amount of adaptation.

There is a set of CR forks on a KDX 'round here somewheres..IC, right?

If you're a machinist, you're home free. Making a custom axle (you're using the KDX wheel I assume?) has been done before here on the KX fork swap. Same sort of thing.

You will need to adapt the KDX stem to the CR bottom clamp. That way the existing head bearings will be the same. Going the other way...looking for bearings to fit the CR stem and the KDX tube may be possible, but much more of a hassle...unless you're Mr. Bearing Catalog Man.

Aha! Here it is:

http://www.kdxrider.net/forums/viewtopi ... ghlight=cr

Not exactly what you're after...but some info on the caliper 'fer instance.

IdahoCharley · Post by **IdahoCharley** » 10:42 am Jan 24 2007

If I recall correctly the CR 125 stem is quite a bit larger in diameter so the lower triple tree would not readily accept the KDX stem. Or maybe I should word it - that it would too readily accept it as in a "drop through".

CC is correct - an option is to turn down the CR stem to the KDX dimensions and use the CR TTs and modifying the CR/KDX fork stops. I consided this but opted for mating the CR forks with a KX TT just due to the fact that it was easier for me and the KX TT off-set was reported by many to work well with the KDX frame and the kdx fender mounting/clearence was a bolt on deal. (unsure of the CR TT off-set)

UFS207 · Post by **UFS207** » 06:03 am Jan 27 2007

If all goes well the seller should be shipping the forks out monday so I should have them by thursday or friday at the latest. If I used a paypal account I'd have them by now....oh well. Really anxious to start this project.

If I skimmed the original post correctly on that link then I can expect the brake caliper to simply mount right up? That is fantastic news if true. As for the steering stem I was batting a few ideas around my head depending on how it (won't) fit. Since you folks say the steering stem diameter is larger on the CR I'd like to turn my own stem out of a piece of 304 or 316 stainless. That way I can use the KDX bearings and keep my stock fork/triple clamp completely unmodified should I find that I like my stock setup better. I'm also somewhat leery of removing material from the CR stem and compromising some strength. Probably won't matter but I'd rather play it safe. I will be using the KDX wheel so I will have to make an axle anyhow, might as well turn a stem while I'm at it.

As for getting the ride hieght correct I was wondering if some type of handle bar risers would allow one to move the forks high enough in the clamps? Seems like that might be an issue. Making the stock fender fit should be as easy as slotting the mounting holes on the fender itself I would think.

Anyways, this will be a learning experience for sure. I will keep you all updated and will post some work in progress pictures as well. Thanks for the help, it is greatly appreciated.

canyncarvr · Post by **canyncarvr** » 10:43 pm Jan 29 2007

Re: 'turning out of...'

And that's where you will be fine. You can MAKE what you need. Us 'JB-Weld-it' 'Ultra Hi-Temp RTV' types ain't that smart.

I don't think you will need bar risers if you do it right. Consider: The farther the top clamp is away from the bottom, the more room you will have to move the fork tubes.

Mentioned before (not here): Measure the 'level' of your bike before you start. Sit it in a place, put a level on the seat/tank so that it IS level. Mark it. With the new forks in you will then have a reference point to 'level' the bike to what it was (measure in the same place, level placed in the same spot, etc.).

Using that approach, my KX forks ('99 KX250) are about 1/2" above the top clamp. A tad too high, as that puts the bottom of the top clamp just a smidge below where the taper starts on the KX forks, but I haven't had a problem with them moving around. I have tweaked them..but running 10ft/lbs. of torque on the clamps to prevent 'stiction', you would have to expect a nose first header into Mother Earth with the forks crammed against the stop is going to tweak SOMEthing.

On a factory setup (race-ready, don'tcha know!!) KTM I've seen forks/bars that look like a pretzeled combination after a simple drop on the nose from 4' up in the air.

Rider ended up with a broken arm..and he had to wedge the front wheel into a tree to 'adjust' it back to normal enough to ride back to the staging area. 'Stuff' happens.

UFS207 · Post by **UFS207** » 12:42 am Feb 18 2007

Thought I would give an update. Overall this has been a pretty straightforward project. I made an axle a week ago and just now got a chance to make the stem today. The axle needs some revisions made to it but I'm pretty happy with the stem. I spent over 3 hours checking demensions on the bike and drawing up a decent print friday night so I could go straight to turning the stem Saturday morning.

Only real hitch was pressing out the CR stem. Like a newbie moron I pressed it out the wrong way! The CR stem took the brunt of the damage (the retainer ring sheared the bottom land of the CR stem off). Surprisingly it took less than 7 tons to do this. Luckily the bore in the lower clamp was fine towards the top and it took less than .030" out of the I.D. with a boring mill to clean up my mistake. In the end it didn't matter as I was making the stem to suit whatever the bore happened to be. Live and learn I guess, only thing ruined was the CR stem which I wasn't using anyway.

Here's a few pics I uploaded of the process:

This is the mock-up fit I did using the unmodified CR frontend. CR bearings are totally different and the bottom clamp actually tightens up against the steering part of the frame.

This is the custom 316 stainless stem installed into the lower CR clamp. The bearings are for the KDX. The aluminum sleeve on the left is to take up the gap created by my desire to raise the top clamp 5/8" above the bearing nut and to allow the smaller stem diameter (.924" at this point) to fit into the larger (1.044") upper clamp. Nuts are from the KDX stem.

This is the assembled CR clamp next to the stock 220 clamp.

Modded CR clamp installed on the bike.

Mostly completed front end shot. Getting the correct ride hieght is no problem at all.

Bars sit about 1/2" higher than stock.

Unfortunately the stock caliper hits the outer diameter of the KDX disk before lining up with the mounting holes. I only need to move it about .150" closer to the centerline of the axle to get it to mount up. I have 3 options that I can tell: make a backplate/mount piece to replace the stock one on the KDX caliper (looks time consuming), buy a slot-less rotor and turn the OD down about 3/8" or I think this thing might work:

http://www.denniskirk.com/jsp/product_c ... mmyId=1500

Plenty of other little things to iron out like the steering stops that just barely catch the bottom of the frame stop, cable routing and figuring out how to mount the stock light.

Anyways, sorry for the long post. Thought it might interest those that are tired of trying to score a set of KX forks for this purpose. If you have access to even a small hobby lathe that'll cut 1.0 pitch metric threads this mod is very doable. Finding someone with a press should be no problem at all....just make sure they press it out the right way! If anyone is interested I'd be more than happy to post my drawings for making the stem and axle.

m0rie · Post by **m0rie** » 10:42 am Feb 18 2007

Looks like its coming together nicely. Please do post the drawings if you get a chance so that they are out there for the peeps to follow if necessary.

canyncarvr · Post by **canyncarvr** » 01:27 am Feb 20 2007

Re: 'This thing might work...'

That would move the caliper farther away from the fork..so, how much farther away does it need to be to and still be properly aligned pad/rotor-wise?

What in the caliper is the obstruction..the brake pins?

IC: How is it your fit worked? Too lazy to go check, but I don't recall which WHEEL you used...

Did you WANT the bars to sit higher? Depending on the postion of the threads on the stem, the forks could just as well be extended past the top of the clamp, correct!

Good job! That stem is purty!!

UFS207 · Post by **UFS207** » 04:54 am Feb 20 2007

I will post all the drawings as soon as I make sure the revisions on the axle are going to work.

Canyncarvr:

I need to move the caliper away from the centerline of the axle at least an 1/8" of an inch, .150" would be ideal. The caliper is hitting on the pins. The linked adapter is for an oversized rotor made by the same company that is 260mm vs the stock KDX rotor at 250mm. 10mm = .394" or .197" per side. So I would think this adapter would move the caliper around .200 away from the C/L of the axle if it has to accommodate a rotor that is nearly .400" larger. Denniskirk.com has a good return policy and I really want to ride next weekend so I think I will give this a shot.

Did you WANT the bars to sit higher? Depending on the postion of the threads on the stem, the forks could just as well be extended past the top of the clamp, correct!

I actually did want the bars higher. I'm bent over a bit standing up with the stock setup and it starts to hurt my lower back after a few hours of riding. I also didn't like having 1/2-5/8" of the forks sticking up past the top clamp. I figured out I could kill two birds with one stone simply by elongating the stem past the bearing nut and using a spacer. If I decide I don't like it all I have to do is make a thinner spacer and stick some washers under the top clamp nut.

Thanks for the replys.

IdahoCharley · Post by **IdahoCharley** » 10:00 am Feb 20 2007

canyncarvr wrote: IC: How is it your fit worked? Too lazy to go check, but I don't recall which WHEEL you used...

I used a 03 CR 250 wheel with 01 CR 125 forks - everything slipped right together associated with the brake. Could have used either the Honda CR caliper or the KDX caliper.

EDIT - The forks were fitted to KX TT and I had slotted aluminum bushings made up adapt the KX TT to the CF forks which were smaller in the upper TT area.

Jeb · Post by **Jeb** » 10:31 pm Feb 21 2007

'Coming along nicely . . .

I, too, have an other-than-KX set of forks - YZs.

I'm interested in how you designed/made your custom axle. 'Made from a piece of some sort of stock?

I see plenty of front YZ axles that would work and they'd come cheap, so I was contemplating buying one and having the 20mm diam portion turned down to 15mm to fit the KDX wheel and then having additional threading added to accept an end piece w/ 20mm OD - something like what KDX220phil did:

Your thoughts?

IdahoCharley · Post by **IdahoCharley** » 11:50 pm Feb 21 2007

My thought it a copy of KDX220 axle approach would be ideal - just select the material to error on the side of strength. I really thought his approach to the axle/wheel swap was the best approach for the masses since the KDX wheel could be used.

Jeb · Post by **Jeb** » 05:58 am Feb 22 2007

IdahoCharley wrote: . . . select the material to error on the side of strength . . .

Do you have a recommendation?

(thanks!)

IdahoCharley · Post by **IdahoCharley** » 11:07 am Feb 22 2007

I do not have a recommendation.

Weakest point will be at the stepdown to the final axle diameter on the fixed portion of the axel. Not the threaded on step-down/spacer.

I would send KDX220Phil a PM and see if he has experienced any problems with the ones he made. He also had performed an material selection process prior to making the axles - as I recall.

P.S. Are the YZ axles hollow?

Jeb · Post by **Jeb** » 05:55 am Feb 23 2007

YZ has a solid axle from what I can tell . . . sorry to hijack your thread ufs207!

UFS207 · Post by **UFS207** » 05:03 pm Mar 03 2007

Jeb, as far as designing the axle I basically just mock fit everything up and went from there. I kept a set of calipers and some paper handy and just jotted down demensions like the through holes on the fork legs, distance between the fork legs and what-not.

The material I used was 316 stainless, same as the stem. I'm not a metallurgist but it is at least as strong as the OEM kawasaki axle material, if not stronger. It is somewhat difficult to machine in comparison to a plain carbon steel. You can see how durable the stuff is as soon as you take a cutting tool to it or try and polish it with emery cloth. I wish I could say something technical about it all but really it boiled down to what kind of stock I could rummage out of my employer's scrap steel rack. Several other grades of stainless like 304 and 416 would work too. 4150, 4140 steel would work great but it will rust.

UFS207 · Post by **UFS207** » 02:11 am Mar 05 2007

Figured I'd give one last update since the swap itself has pretty much come to a close. Rode the bike around for about 3 hours today and it felt nice. Ride height is perfect. Fork springs feel slightly stiffer than the .40kg springs in my stockers but not objectionly so. Definately feels more planted through rocks and ruts if you are carrying any speed.

Heres a few more in-process pics:

Above is the finshed axle assembly. Used 316 stainless here as well. Axle threads into the "nut" on the far right. Spacer in the middle takes the place of the stock KDX spacer on the brake caliper side.

Steering stop fix. Water-jetted from 1/2" T304 stainless plate and secured with two set screws on the top. I lost some steering angle going this route but it didn't involve any permanate modifying. Didn't pose any problems on the tight singletrack I rode today.

Odometer holder. This keeps the odometer from free-wheeling with the wheel itself. Ugly, but it works. Water-jetted from 1/8" thick T304 stainless plate.

Here is the oversize caliper-mount I linked to previously. Worked perfectly. Real lucky find.

Finished product. If anything I think the bike looks better.

A few closing thoughts for anyone interested in a similar swap:

Try and get a complete frontend. Not sure what changed over the years with the CR frontends but I can tell you my setup is from a 2001 CR125R. You will lose the stock odometer but you won't have to worry about a custom axle OR the caliper mount.

If you don't have access to a lathe I would guesstimate a typical job-shop would charge around $200-$250 to turn the stem and spacer. It took me a little over 4 hrs to do mine and most shops charge 40-60 an hour. I figure $40 or so for the material. Might seem like alot for just the stem BUT if you have a complete CR frontend the custom stem/spacer is all you need that would require lathe-work. Another alternative for cheaper machine work would be to check with a local community/tech school with metal working programs. Alot of them will take on outside work for not much more than tooling/material costs to use as teaching aids.

I will upload my figures and drawings as soon as I have time to make them legible.

Jeb · Post by **Jeb** » 05:31 am Mar 05 2007

Very nice! Your machining ideas are very creative. And thanks for the info on both the stem/axle MOC and shop cost estimates - very handy info!

Did you "divot" at all the top of the original steering stop so that the set screws on your custom steering stop could lock on? Or are the set screws strong enough to prevent the custom piece from falling off?

I agree with your assessment on "complete front end". I ended up getting YZ tire/hub and then an axle/spacers, albeit different years than the forks. This assembly is going to work with the stock KDX calipers, and I think Idaho Charlie's CR setup worked out the same way (calipers fit). On the other hand, we don't have the luxury of using the stock odometer!

Thanks again, your bike looks great!

IdahoCharley · Post by **IdahoCharley** » 10:00 am Mar 05 2007

Looks good and still have the Odometer!!

KDXRIDER.NET

KDXRIDER.NET

01 CR125 forks on a 220

01 CR125 forks on a 220